Is it wrong to use local variables in "loop" ?
If you want them to retain their value between iterations of loop() even if is changed then declare them static. They will be initialised with the value given and if changed in loop() they will not be reinitialised. If you don't declare them static then they will be reinitialised each time through loop().
static int staticInt = 0;
int nonStaticInt = 0;
Serial.print("static : ");
Serial.print("non static : ");